<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        html, body {
            height: 100%;
        }
        .parent{
            height: 100vh;
            display: flex;
            /*flex-direction: column;*/
        }
        .child{
            flex:1;
            height: 100px;
        }
        /*.child + .child{*/
        /*    margin-left: 20px;*/
        /*}*/
    </style>
</head>
<body>
<div class="parent" style="background-color: lightgrey;">
    <div class="child" style="background-color: lightblue; overflow: auto">圣诞节啊<br><br><br><br><br><br><br><br>地方就是看<br><br><br><br>水电费</div>
    <div class="child" style="background-color: lightgreen;">2</div>
    <div class="child" style="background-color: lightsalmon;">3</div>
    <div class="child" style="background-color: pink;">4</div>
</div>
</body>
</html>
